Recently, electronic devices that incorporate touch panels therein have been spreading widely. Touch panels are mounted in many devices including small screen, such as portable phones, PDAs (Personal Digital Assistants), or the like. In the future, it can be envisaged sufficiently that such touch panels will be incorporated into equipment having large sized screens that serve as PC (Personal Computer) displays or the like.
In the case of conventional touch panel electrodes, indium tin oxide (ITO: Indium Tin Oxide) primarily is used in view of the translucent properties thereof. It is known that the electric resistance per unit area of ITO is comparatively high compared to other metals or the like. More specifically, in the case of ITO, as the (total area of the touch panel) screen size increases, the surface resistivity in the electrode as a whole tends to increase. As a result, a problem arises in that the transmission speed of current between the electrodes becomes slower, such that the time (i.e., response speed) required to detect the contact position after the touch panel has been touched is delayed.
Therefore, various techniques have been proposed in which surface resistivity is decreased by constituting the electrodes in plurality, in the form of a lattice by means of thin wires (thin metal wires) made up from metals having low electrical resistance (see, for example, International Publication No. 1995/27334, International Publication No. 1997/18508, and Japanese Laid-Open Patent Publication No. 2003-099185).